Oracle 11g cannot export empty tables

Friends who use Oracle 11G may have struggled with this problem. The data exported by the exp command may be inexplicably missing some tables, during the analysis, we will find that these tables are empty tables with no records inserted. The cause is that oracle 11g introduces a new feature. When the new table is not inserted, the server does not create a segment for this table by default to save storage space, therefore, when exporting data, empty table information cannot be exported, resulting in program errors.

Solution:

Modify configuration parameters

Sqlplus/nolog

SQL> connect system/password as sysdba;

SQL> show parameter deferred_segment_creation;

The default value is true.

SQL> alter system set deferred_segment_creation = false;

Restart the oracle service.

A new table created later can be exported without inserting data. However, the empty table before changing the parameters still does not have a segment. You need to manually insert data to the table to generate a segment.